The primary role of transfer RNA(tRNA)is to connect a specific amino acid to its 3' end, use its anticodon to match the codon on messenger RNA(mRNA), and deliver the corresponding amino acid to the ribosome for protein synthesis.tRNA exists in two forms: precursor tRNA and mature tRNA.When acted upon by enzymes like Dicer, elaC ribonuclease Z 2(ELAC2), angiopoietin(ANG), and other ribonucleases, tRNA is broken down into tRNA-derived stress-induced RNA(tiRNA)and tRNA-derived fragments(tRF).Recent advancements in RNA sequencing technology have led to increased interest in tiRNA and tRF, shedding light on their roles in various physiological and pathological processes.tRNA-derived small molecules(tsRNA)function similarly to microRNA(miRNA), influencing gene expression and protein synthesis.They show promise as diagnostic markers and potential therapeutic targets for age-related diseases.This review offers a comprehensive analysis of tsRNA classification, biological functions, research advancements, and clinical applications in age-related conditions.

With the extension of the global population's lifespan and the increasingly severe aging problem,cardio-vascular diseases have become the leading cause of death among the elderly population.Most cardiovascular diseases orig-inate from the formation of atherosclerotic plaques.In addition to common risk factors such as dyslipidemia,diabetes,hy-pertension,smoking,and obesity,circadian rhythm disruption is also regarded as an important but often overlooked risk factor for atherosclerosis.The circadian rhythm is involved in regulating key physiological processes such as inflammation and metabolism,which in turn affect the pathological processes of arteriosclerosis and thrombosis.In this process,the key genes that maintain the stability of the circadian rhythm,namely clock gene,play a crucial role.Clock gene have an important role in the pathological mechanism of atherosclerosis,and they may become potential new targets for the preven-tion and treatment of atherosclerosis.This paper reviews the latest research progress on the mechanism of action of clock gene in the occurrence and development of atherosclerosis.These findings may provide new ideas for the diagnosis and treatment of atherosclerosis.

With the extension of the global population's lifespan and the increasingly severe aging problem,cardio-vascular diseases have become the leading cause of death among the elderly population.Most cardiovascular diseases orig-inate from the formation of atherosclerotic plaques.In addition to common risk factors such as dyslipidemia,diabetes,hy-pertension,smoking,and obesity,circadian rhythm disruption is also regarded as an important but often overlooked risk factor for atherosclerosis.The circadian rhythm is involved in regulating key physiological processes such as inflammation and metabolism,which in turn affect the pathological processes of arteriosclerosis and thrombosis.In this process,the key genes that maintain the stability of the circadian rhythm,namely clock gene,play a crucial role.Clock gene have an important role in the pathological mechanism of atherosclerosis,and they may become potential new targets for the preven-tion and treatment of atherosclerosis.This paper reviews the latest research progress on the mechanism of action of clock gene in the occurrence and development of atherosclerosis.These findings may provide new ideas for the diagnosis and treatment of atherosclerosis.

The primary role of transfer RNA(tRNA)is to connect a specific amino acid to its 3' end, use its anticodon to match the codon on messenger RNA(mRNA), and deliver the corresponding amino acid to the ribosome for protein synthesis.tRNA exists in two forms: precursor tRNA and mature tRNA.When acted upon by enzymes like Dicer, elaC ribonuclease Z 2(ELAC2), angiopoietin(ANG), and other ribonucleases, tRNA is broken down into tRNA-derived stress-induced RNA(tiRNA)and tRNA-derived fragments(tRF).Recent advancements in RNA sequencing technology have led to increased interest in tiRNA and tRF, shedding light on their roles in various physiological and pathological processes.tRNA-derived small molecules(tsRNA)function similarly to microRNA(miRNA), influencing gene expression and protein synthesis.They show promise as diagnostic markers and potential therapeutic targets for age-related diseases.This review offers a comprehensive analysis of tsRNA classification, biological functions, research advancements, and clinical applications in age-related conditions.

Objective:To evaluate the role of transient receptor potential vanillic acid 4 (TRPV4) in dexmedetomidine-induced improvement in cognitive function in mice with mechanical ventilator-caused brain injury.Methods:Ninety clean-grade healthy male C57BL6 mice, weighing 20-25 g, aged 8-12 weeks, were divided into 5 groups ( n=18 each) using a random number table method: control group (group C), mechanical ventilation group (group V), HC-067047 group (group H), dexmedetomidine group (group D), and dexmedetomidine+ GSK1016790A group (group DG). In group C, the animals breathed air spontaneously for 6 h without mechanical ventilation. In group V, the animals were mechanically ventilated for 6 h. In group H, TRPV4 blocker HC-067047 10 mmol was injected into the cerebral ventricle at 3 and 6 h of mechanical ventilation. In D and DG groups, dexmedetomidine 50 μg/kg was intraperitoneally injected at 30 min before mechanical ventilation. In group DG, TRPV4 agonist GSK1016790A 5 μmol was injected into the cerebral ventricle at 60 min before mechanical ventilation. Morris water maze test was performed on 6 mice in each group at 1 day before mechanical ventilation and 3 and 7 days after mechanical ventilation. Six mice in each group were randomly selected and sacrificed at 1 day after mechanical ventilation, and the brain tissue was taken for determination of the neuronal apoptosis in hippocampal CA1 area by TUNEL method, and the apoptosis index was calculated. Six mice in each group were randomly selected and sacrificed at 1 day after mechanical ventilation, and the hippocampal tissues were taken for determination of the expression of TRPV4, serine-threonine protein kinase (Akt), phosphorylated Akt (p-Akt), Bcl-2, Bax and caspase-3 by Western blot. Results:Compared with group C, the escape latency was significantly prolonged and the number of crossing the original platform was reduced at 3 and 7 days after mechanical ventilation, the expression of TRPV4 and caspase-3 was up-regulated, the ratio of Bcl-2/Bax was decreased, and the apoptosis index of neurons was increased in group V and group DG ( P<0.05). Compared with group V, the escape latency was significantly shortened and the number of crossing the original platform was increased at 3 and 7 days after mechanical ventilation, the expression of TRPV4 and caspase-3 was down-regulated, the expression of p-Akt was up-regulated, the ratio of Bcl-2/Bax was increased, and the apoptosis index of neurons was decreased in group D and group H ( P<0.05). Compared with group D, the escape latency was significantly prolonged at 3 and 7 days after mechanical ventilation, the number of crossing the original platform was reduced, the expression of TRPV4 and caspase-3 was up-regulated, the expression of p-Akt was down-regulated, the ratio of Bcl-2/Bax was decreased, and the apoptosis index of neurons was increased in group DG ( P<0.05). Conclusions:TRPV 4 is involved in dexmedetomidine-induced improvement in cognitive function, which is related to up-regulation of p-Akt expression and inhibition of apoptosis in hippocampal neurons in mice with mechanical ventilation-caused brain injury.

Objective:To investigate the effect of baicalin on cognitive function of mice with brain injury induced by mechanical ventilation and its mechanism.Methods:Seventy two C57BL6 mice, weighing 20-25 g, aged 8-12 weeks, were randomly divided into control group (group C), mechanical ventilation group (group V), baicalin group (group B), baicalin+ Akt inhibitor MK-2206 group (group BM) according to random number table method, with 18 in each group.Mice in group C did not have mechanical ventilation and breathed air independently for 6 hours.Mice in group V received mechanical ventilation for 6 hours.Mice in group B and group BM were intraperitoneally injected with baicalin 100 mg/kg 30 minutes before mechanical ventilation, and mice in group BM were injected intraventricular with Akt inhibitor MK-2206 300 μg/kg 60 minutes before mechanical ventilation.Six mice in each group were randomly selected to test their learning and memory abilities by Morris water maze test 1st day before mechanical ventilation and 3rd day and 7th day after mechanical ventilation.One day after mechanical ventilation, six mice in each group were killed, and the brain tissue was taken.TUNEL method was used to detect the neuronal apoptosis in hippocampal CA1 area, and the apoptosis index was calculated.One day after mechanical ventilation, six mice in each group were killed, and the hippocampus was taken, Western blot was used to detect the protein expressions of caspase-3, caspase-9, Akt, p-Akt, GSK-3β and p-GSK-3β.SPSS 22.0 software was used for statistical analysis of data, repeated measure ANOVA and one-way ANOVA were used for comparison between multiple groups.LSD- t test was used for further pairwise comparison. Results:The results of water maze test showed that the time and group interaction of the four groups were not significant ( F=1.14, P>0.05), the main effect of time and group were both significant ( F=47.36, 59.65, both P<0.05). At 3rd day and 7th day after mechanical ventilation, the escape latencies of mice in group V were higher than those in group C (both P<0.05), and the numbers of platform crossing were lower than those in group C (both P<0.05). And 3 days and 7 days after mechanical ventilation, the escape latencies of mice in group B were lower than those in group V (both P<0.05) and the numbers of platform crossing were higher than those in group V (both P<0.05). The escape latenies of mice in BM group on the 3rd and 7th day were higher than those in group B (both P<0.05), and the numbers of platform crossing were lower than those in group B on the 3rd day and 7th day after mechanical ventilation(both P<0.05). TUNEL and Western blot results showed that apoptosis index of hippocampal neurons and expression levels of apoptosis-related proteins caspase-3 and caspase-9 were significant different in the four groups ( F=51.42, 41.21, 40.19, all P<0.05). The apoptosis index of hippocampal neurons ((40.6±3.9)%), the expression levels of caspase-3 (4.93±0.92) and caspase-9 (4.81±0.88) in the hippocampus of mice in group V were higher than those in group C ((13.7±1.4)%, (1.87±0.27), (1.71±0.25), all P<0.05), the apoptosis index of hippocampal neurons ((15.6±1.6)%), the expression levels of caspase-3 (1.95±0.30) and caspase-9 (1.76±0.28) in group B were lower than those in group V ((40.6±3.9)%, (4.93±0.92), (4.81±0.88), all P<0.05), the apoptosis index of hippocampal neurons ((27.8±2.7)%), the expression levels of caspase-3 (3.58±0.61) and caspase-9 (3.49±0.57) in BM group were higher than those in group B ((15.6±1.6)%, (1.95±0.30), (1.76±0.28), all P<0.05). Expression level of p-Akt, p-GSK-3β in hippocampal tissues of the four group of mice were significantly different ( F=37.54, 43.23, both P<0.05). The expression level of p-Akt (0.51±0.06) and p-GSK-3β (0.47±0.05) of hippocampal tissues of mice in group V were lower than those of group C ((1.07±0.10), (1.11±0.12), both P<0.05), the expression level of p-Akt (0.99±0.10) and p-GSK-3β (1.08±0.09) of hippocampal tissues of mice in group B were higher than those of group V (both P<0.05), the expression level of p-Akt (0.83±0.08) and p-GSK-3β (0.81±0.07) of hippocampal tissues of mice in group BM were lower than those in group B (both P<0.05). Conclusion:Baicalin can improve the cognitive function of mice with brain injury induced by mechanical ventilation, which is related with activation of Akt/GSK-3β signaling pathway and inhibition of hippocampal neuron apoptosis.

Objective:To evaluate the effects of dexmedetomidine on alveolar epithelial barrier function in rats with ventilator-induced lung injury (VILI), and the role of protein kinase C (PKC).Methods:One hundred clean-grade male Sprague-Dawley rats, weighing 270-320 g, aged 4-5 months, were divided into 5 groups ( n=20 each) using a random number table method: control group (group C), VILI group (group V), PKC inhibitor group (group B), dexmedetomidine group (group D), and dexmedetomidine plus PKC agonist group (DP group). The VILI model was developed by mechanical ventilation with a tidal volume of 40 ml/kg for 4 h in anesthetized animals.Group C breathed air autonomously for 4 h without mechanical ventilation.Group V was mechanically ventilated for 4 h. In group B, bisindolvlmaleimide I 0.12 mg/kg was injected intramuscularly 1 h before mechanical ventilation.In D and DP groups, dxmedetomidine 5.0 μg/kg was injected intravenously at 20 min before mechanical ventilation, and dexmedetomidine was intravenously infused at the rate of 5.0 μg·kg -1·h -1 during mechanical ventilation.In group DP, PKC agonist phorbol-12-myristic acid-13-acetate 15 μg/kg was intraperitoneally injected at 30 min before mechanical ventilation.At 4 h of mechanical ventilation, oxygenation index (OI), lung permeability index (LPI) and wet/dry lung weight (W/D) ratio were measured, the pathological changes of lung tissues were observed, and lung injury was assessed and scored.The expression of PKC, occludin and ZO-1 protein was detected by Western blot, and the expression of PKC mRNA, occludin mRNA and ZO-1 mRNA was determined by real-time polymerase chain reaction. Results:Compared with group C, OI was significantly decreased, LPI, W/D ratio and lung injury score were increased, the expression of PKC protein and mRNA was up-regulated, and the expression of occludin and ZO-1 protein and mRNA was down-regulated in V and DP groups ( P<0.05), and no significant change was found in the parameters mentioned above in B and D groups ( P>0.05). Compared with group V, OI was significantly increased, LPI, W/D ratio and lung injury score were decreased, the expression of PKC protein and mRNA was down-regulated, and the expression of occludin and ZO-1 protein and mRNA was up-regulated in B, D and DP groups ( P<0.05). Compared with group D, OI was significantly decreased, LPI, W/D ratio and lung injury score were increased, the expression of PKC protein and mRNA was up-regulated, and the expression of occludin and ZO-1 protein and mRNA was down-regulated in group DP ( P<0.05). Conclusions:Dexmedetomidine can reduce the damage to alveolar epithelial barrier function in rats with VILI, and the mechanism is related to inhibition of PKC activation and up-regulation of the expression of occludin and ZO-1.

Objective:To evaluate the role of transient receptor potential vanilloid receptor 1 (TRPV1)/nuclear factor-κB (NF-κB) signaling pathway in dexmedetomidine-induced alleviation of ventilator-induced lung injury (VILI) in rats.Methods:One hundred clean-grade healthy male Sprague-Dawley rats, weighing 270-320 g, aged 4-5 months, were divided into 5 groups ( n=20 each) using a random number table method: control group (group C), VILI group (group V), AMG9810 group (group A), dexmedetomidine group (group D), and dexmedetomidine + RTX group (group DR). VILI model was prepared by mechanical ventilation with a tidal volume of 40 ml/kg for 4 h. In group A, TRPV1 inhibitor AMG9810 30 mg/kg was intraperitoneally injected at 1 h before mechanical ventilation.Dexmedetomidine 5.0 μg/kg was intravenously infused at 20 min before mechanical ventilation, and dexmedetomidine was intravenously infused at the rate of 5.0 μ g·kg -1·h -1 during ventilation in group D and group DR.In group DR, RTX 70 μ g/kg was intraperitoneally injected for 3 consecutive days before mechanical ventilation.At 4 h of mechanical ventilation, the concentrations of interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and IL-6 in bronchoalveolar lavage fluid (BALF) were detected, oxygenation index (OI) and wet/dry lung weight (W/D) ratio were measured, the histopathological changes of lung tissues were observed, and lung injury was assessed and scored.The expression of TRPV1 and NF-κB in lung tissues was detected by Western blot, and real-time polymerase chain reaction was used to detect the expression of TRPV1 and NF-κB mRNA. Results:Compared with group C, the concentrations of IL-1β, TNF-α and IL-6 in BALF were significantly increased, OI was decreased, the W/D ratio and lung injury scores were increased, and the expression of TRPV1 and NF-κB protein and mRNA was up-regulated in group V ( P<0.05). Compared with group V, the concentrations of IL-1β, TNF-α and IL-6 in BALF were significantly decreased, OI was increased, the W/D ratio and lung injury scores were decreased, and the expression of TRPV1 and NF-κB protein and mRNA was down-regulated in A, D and DR groups ( P<0.05). Compared with group D, the concentrations of IL-1β, TNF-α and IL-6 in BALF were significantly increased, OI was decreased, the W/D ratio and lung injury scores were increased, and the expression of TRPV1 and NF-κB protein and mRNA was up-regulated in group DR ( P<0.05). Conclusions:The mechanism by which dexmedetomidine alleviates VILI is partially related to inhibition of the activation of TRPV1/NF-κB signaling pathway and inhibition of the inflammatory responses in lung tissues of rats.

Objective:To evaluate the effect of dexmedetomidine on the extracellular signal-regulated kinase(ERK)/sodium-potassium ATPase(Na + -K + -ATPase)signaing pathway in lung tissues of rats with mechanical ventilation-induced lung injury (VILI). Methods:Forty-eighty clean-grade male Sprague-Dawley rats, weighing 270-320 g, aged 4-5 months, were divided into 4 groups ( n=12 each) using a random number table method: control group (group C), VILI (alpha2-adrenergic receptor antagonist) group (group V), dexmedetomidine group (group D), and dexmedetomidine plus yohimbine group (group DY). Group C underwent no mechanical ventilation and breathed air spontaneously for 4 h. Mechanical ventilation (respiratory rate 40 breaths/min, tidal volume 40 ml/kg, inspiratory/expiratory ratio 1∶1, PEEP 0, fraction of inspired oxygen 21%) lasted 4 h in group V. Dexmedetomidine was infused intravenously in a dose of 5.0 μg/kg at 20 min before ventilation followed by an infusion of 5.0 μg·kg -1· h -1 throughout ventilation in group D. In group DY, yohimbine 0.1 mg/kg was injected intravenously at 10 min before dexmedetomidine, and the other treatments were similar to these previously described in group D. Blood samples and lung tissues were taken at 4 h of mechanical ventilation to determine the wet/dry weight ratio (W/D ratio), lung permeability index (LPI), alveolar fluid clearance rate (AFC), and expression of extracellular signal-regulated kinase (ERK), phosphorylated extracellular signal-regulated kinase (p-ERK), and Na + -K + -ATPase in lung tissues (by Western blot) and to observe pathological changes of lung tissues. Results:Compared with group C, LPI and W/D ratio were significantly increased, AFC was decreased, p-ERK expression was up-regulated, and Na + -K + -ATPase expression was down-regulated in group V and group DY ( P<0.05), and no significant change was found in the incidence of the parameters mentioned above in group D ( P>0.05). Compared with group V, LPI and W/D ratio were significantly decreased, AFC was increased, p-ERK expression was down-regulated, Na + -K + -ATPase expression was up-regulated ( P<0.05), and the pathological changes of lung tissues were significantly attenuated in group D, and no significant change was found in the incidence of the parameters mentioned above in group DY ( P>0.05). Compared with group D, LPI and W/D ratio were significantly increased, AFC was decreased, p-ERK expression was up-regulated, Na + -K + -ATPase expression was down-regulated ( P<0.05), and the pathological changes of lung tissues were accentuated in group DY. Conclusion:The mechanism by which dexmedetomidine alleviates VILI may be related to activating alpha2-adrenergic receptors and inhibiting ERK/Na + -K + -ATPase signaling pathway in rats.

Objective To analyze the effects of Hual qi huang granules on children with mycoplasma pneumoniae pneumonia.Methods A randomized,multicenter parallel controlled clinical trial was carried out.A total of 3 000 cases of hospitalized children with mycoplasma pneumoniae pneumonia were selected.All of them were given treatment for mycoplasma pneumoniae pneumonia with macrolide antibiotics and symptomatic treatment.They were randomly divided into 2 groups:research group and control group.The children of research group were give oral Huai qi huang granules for three months.According to the classification of pneumonia,these two groups were divided into:lobar pneumonia research group,lobar pneumonia control group,lobular pneumonia research group,lobular pneumonia control group.The hospitalization duration of fever,length of hospital stay,the absorption area of lung inflammation and pneumonia severity sores were observed.The frequency of upper respiratory infections,bronchitis,pneumonia were observed in 3 months after discharge.Results 2 378 cases were investigated.The hospitalization duration of fever,length of hospital stay of research group were significantly shorter than that of in control group (P ＜ 0.001).The children with lobar pneumonia,2 weeks after treatment,the absorption of consolidation of the lobar pneumonia research group is significantly better than lobar pneumonia control group (P ＜0.001).After two weeks treatment,the pneumonia scores of lobar pneumonia research group is lower than lobar pneumonia control group (P ＜ 0.05).Followup of 3 months after hospital discharge,frequency of upper respiratory infection and bronchitis of research group,were significantly lower than that of control.In addition,appetite increased significantly in research group than control (P ＜ 0.001).There are 21 cases with drug associated adverse reactions (mild diarrhea),including 12 cases of research group,9 cases of control group,and there was no statistical significance (P ＞0.05).Conclusion Standard treatment combined with oral Huai qi huang granules in the treatment of mycoplasma pneumoniae pneumonia,can significantly shorten hospitalization duration of fever,length of hospital stay and reduce the severity score of pneumonia.Three months oral Huai qi huang granules can significant reduce the frequency of respiratory infections and bronchitis,also can increase patients appetite,and be safe.